My time off is sporadic and unpredictable. If I have a day off and am in the mood, I will sometimes call to see if there is availability. I am always apologetic and polite and explain my situation. Most times I just ask if the lady can be available, that day, at a time of her choosing. Most ladies have been amenable, if not always able to accommodate. I do, however prefer to make advance arrangements, whenever possible and I never take offense, if a same day arrangement is not possible.